data = open('sketch.txt')
data.seek(0)
for each_line in data:
#   if not each_line.find(':') == -1: # Not取反
    if each_line.find(':') != -1: # == -1 为没找到冒号，!= -1 为找到冒号
        (role, spoken) = each_line.split(':', 1) #只在遇到第一个：时分割
        print(role, end='')
        print('said', end='')
        print(spoken, end='')
data.close()